Wed·Oct 31, 2001Wednesday·October 31, 2001

1. 01*

   From Spin Ladders to the 2-d O(3) Model at Non-Zero Density

   S. Chandrasekharan🇺🇸 · B. Scarlet🇺🇸 · U.-J. Wiese🇺🇸

   The numerical simulation of various field theories at non-zero chemical potential suffers from severe complex action problems. In particular, QCD at non-zero quark density can presently not be simulated for that reason. A similar complex action problem arises in the 2-d O(3) model -- a toy model for QCD. Here we construct the 2-d O(3) model at non-zero density via dimensional reduction of an antiferromagnetic quantum spin ladder in a magnetic field. The complex action problem of the 2-d O(3) model manifests itself as a sign problem of the ladder system. This sign problem is solved completely with a meron-cluster algorithm.

   hep-latComput.Phys.Commun.(2002)·17 citations
2. 02*

   Hadron Masses From Novel Fat-Link Fermion Actions

   J. M. Zanotti🇦🇺 · S. Bilson-Thompson🇦🇺 · F. D. R. Bonnet🇦🇺 · P. D. Coddington🇦🇺 · D. B. Leinweber🇦🇺 · A. G. Williams🇦🇺 · J. B. Zhang🇦🇺 · W. Melnitchouk🇺🇸 · F. X. Lee🇺🇸

   The hadron mass spectrum is calculated in lattice QCD using a novel fat-link clover fermion action in which only the irrelevant operators in the fermion action are constructed using smeared links. The simulations are performed on a 16^3 x 32 lattice with a lattice spacing of a=0.125 fm. We compare actions with n=4 and 12 smearing sweeps with a smearing fraction of 0.7. The n=4 Fat-Link Irrelevant Clover (FLIC) action provides scaling which is superior to mean-field improvement, and offers advantages over nonperturbative 0(a) improvement, including a reduced exceptional configuration problem.

   hep-latPRD(2002)·125 citations
3. 03*

   Nonperturbative Lattice Simulation of High Multiplicity Cross Section Bound in ${\varphi }_3^4$ on Beowulf Supercomputer

   Yeo-Yie Charng🇺🇸

   In this thesis, we have investigated the possibility of large cross sections at large multiplicity in weakly coupled three dimensional ${\varphi }^4$ theory using Monte Carlo Simulation methods. We have built a Beowulf Supercomputer for this purpose. We use spectral function sum rules to derive a bound on the total cross section where the quantity determining the bound can be measured by Monte Carlo simulation in Euclidean space. We determine the critical threshold energy for large high multiplicity cross section according to the analysis of M.B. Volosion and E.N. Argyres, R.M.P. Kleiss, and C.G. Papadopoulos. We compare the simulation results with the perturbation results and see no evidence for large cross section in the range where tree diagram estimates suggest they should exist.

   hep-lathep-ph1 citation
4. 04*

   Ginsparg-Wilson fermions: practical aspects and applications

   P. Hernandez (CERN)🇨🇭

   I review recent progress in the implementation of lattice fermions satisfying the Ginsparg-Wilson relation and some physical applications.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·24 citations
5. 05*

   Screening Masses in Dimensionally Reduced (2+1)D Gauge Theory

   P. Bialas🇵🇱 · A. Morel🇫🇷 · B.Petersson🇩🇪 · K. Petrov🇩🇪

   We discuss the screening masses and residue factorisation of the SU(3) (2+1)D theory in the dimensional reduction formalism. The phase structure of the reduced model is also investigated.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·5 citations
6. 06*

   Pion Decay Constant, $Z_A$ and Chiral Log from Overlap Fermions

   S.J. Dong🇺🇸 · T. Draper🇺🇸 · I. Horvath🇺🇸 · F.X. Lee🇺🇸 · J.B. Zhang🇦🇺

   We report our calculation of the pion decay constant $f_{\pi }$, the axial renormalization constant $Z_A$, and the quenched chiral logarithms from the overlap fermions. The calculation is done on a quenched $20^4$ lattice at $a=0.148$ fm using tree level tadpole improved gauge action. The smallest pion mass we reach is about 280 MeV. The lattice size is about 4 times the Compton wavelength of the lowest mass pion.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·4 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.